For patients with coronary artery disease (CAD) who cannot undergo full revascularization, mortality rates are significantly higher and researchers say more treatment options need to be made available for this patient cohort, according to a study published May 1 in Catheterization and Cardiovascular Interventions.
“Despite medical therapy, a majority of patients are diagnosed with refractory angina, “a chronic condition characterized by the presence of angina caused by coronary insufficiency in the presence of CAD which cannot be controlled by a combination of medical therapy, angioplasty and coronary bypass surgery.”
Because outcomes of patients with refractory angina are scant, Benjamin Williams, MD, of the Minneapolis Heart Institute at the Abbott Northwestern Hospital in Minneapolis, and colleagues evaluated 493 CAD patients undergoing PCI or CABG between July 2005 and August 2005 to evaluate three-year mortality rates and the prevalence of patients unable to be revascularized.
After obtaining results from angiographies, patients were split into six groups: 1) normal coronaries; 2) stenosis less than 70 percent; 3) stenosis greater than 70 percent with complete revascularization; 4) stenosis greater than 70 percent with partial revascularization; 5) stenosis greater than 70 percent without revascularization treated with medical therapy; and 6) stenosis greater than 70 percent with no revascularization options besides medical therapy.
Options for patients in group six were stressed due mostly to chronic total occlusion (70 percent), diffuse disease (46 percent) and collateral dependent perfusion (42 percent).
During the study, 28.8 percent of patients had CAD and did not undergo complete revascularization with PCI or CABG, 12.8 percent were partially revascularized, 9.3 percent were medically managed and 6.7 percent of patients had no medical therapy options or option to undergo revasculariztion.
Mortality rates for patients with “no options” were 15.2 percent at three years and 17.4 percent for patients with stenosis greater than 70 percent treated with medical therapy and no revascularization (group 5).
Compared to group four, which included patients with CAD who underwent partial revascularization (groups 4-6), and patients who did not undergo revascularization (groups 1-3), mortality risk was 14.8 percent versus 6.6 percent.
According to the researchers, patients who underwent partial revascularization were more likely to be male, older in age and have higher rates of comorbidities including hypertension, diabetes and peripheral artery disease.
“Reasons for the improvement in mortality are unclear but are likely associated with advances in medical therapy for patients with CAD,” the authors concluded. “This growing patient population is in need of novel therapeutic strategies aimed at improving not only mortality but also quality of life."
In an accompanied editorial, Ran Kornowski, MD, of the Rabin Medical Center, Tel Aviv University in Israel, wrote, “This elegant study is important, because it teaches us that suboptimal revascularization is probably more common in our daily practice than we tend to think.”
However, Kornowski said evaluation of myocardial ischemia in the trial was absent.
While Kornowski agreed with Williams et al, he said, "To improve risk stratification, one may consider to evaluate systematically and periodically the ischemic burden and myocardial function of these patient,” due to the fact that previous studies have shown that cardiac prognosis may be a reflection of ischemic burden.